Leaves turning upside down why??

So I've had this issue arise I've never encountered before I'm not a professional but I'm not a noob either I have a few Cycles under my belt with little to no major issues but I just came across an issue where my leaves will just flip over it's not any specific area it's a mobile issue I'm not sure if I need to post a picture I think most people could visualize what a leaf upside down looks like let me know if there's any kind of things I should be looking for thanks in advance

Light used and distance? Upper leaf?

It's a mobile issue on one plant only 8bulb power veg t5 at 16" I thought the same thing but only one plant. I've narrowed it down to a potassium deficiency (lock out) stems are very bendy and noticed thin red stripes starting to show up. Emerald harvest "micro" nuit. Is basically the same thing as the cali-magc from general organics been giving double feedings of cal-mag.. DEERP. READ THE LABELS